1. Technical Field
The invention relates to a droplet ejection head that performs recording of images by ejecting droplets, for example, by an ink jet recording method, as well as to a method of manufacturing the droplet ejection head, and a droplet ejection apparatus provided with the droplet ejection head.
2. Related Art
Conventionally, ink jet recording apparatuses are known as droplet ejection apparatuses that perform printing on a recording medium such as a paper sheet by ejecting droplets from plural nozzles. These ink jet recording apparatuses are widely commercially available because of having the various advantages such as being small, inexpensive, and quiet. In particular, recording apparatuses of piezoelectric ink jet type that eject ink droplets by changing the pressure within a pressure chamber with the use of a piezoelectric element, or recording apparatuses of thermal ink jet type that eject ink droplets by expanding the ink with the use of the action of thermal energy, have numerous advantages such as providing high-speed printing and high resolution.
In such ink jet type recording apparatuses, in the ink jet recording head, problems are caused, such as adhesion of ink droplets to the periphery of the nozzle when the ink droplets are ejected from the nozzle or leakage of ink due to the overshoot phenomenon in which the ink wells out from the nozzle. Therefore, inclination of the direction of ink ejection or fluctuations in the droplet diameter of the ink or speed may occur, and thereby the printing property of the ink jet recording head may be significantly degraded. In view of this, the surface of the nozzle is coated with a water-repellent film so as to prevent ink droplets from adhering to the periphery of the nozzle.
The thickness of the above-described water-repellent film is made thin from the point of view of nozzle-forming properties or ejection stability. On the other hand, reduced thickness of the water-repellent film causes problems such as insufficient scratch resistance. Similar problems lie not only in ink jet recording heads but also in droplet ejecting heads in general.